Area Forecast Discussion
Issued by NWS Dallas/Fort Worth, TX

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS64 KFWD 252100
AFDFWD

Area Forecast Discussion
National Weather Service Fort Worth TX
400 PM CDT Sat Mar 25 2017

.DISCUSSION...
Mostly sunny skies and pleasant temperatures prevail across North
Texas behind last night`s cold front. West-northwest winds have
ushered in some drier air making for a nice day across the region.
Temperatures are generally in the 60s and 70s with dewpoints in
the 40s.

Springtime usually means rapidly changing weather as the upper
pattern is usually fairly progressive. Tomorrow will be no
different. Shortwave ridging today and tonight will give way to a
fast moving shortwave trough by tomorrow and increasing severe
weather chances. As the upper disturbance approaches, rapid
surface cyclogenesis will commence during the morning hours. This
will result in strengthening southerly flow and a rapid northward
transport of moisture. By midday, surface dewpoints will likely
be near 60 degrees along the I-35 corridor toward to the Red
River. In addition, a dryline will advance eastward across West-
Central Texas.

By late afternoon, an elevated mixed layer will be in place across
North Texas resulting in a capping inversion around 800mb with
very steep lapse rates through about 500mb. Even as the main
shortwave tracks across northern Oklahoma, stronger forcing for
ascent will spread into North Texas by late afternoon. This should
help to lift the capping, which is not expected to be overly
strong. We`ll likely sample this with supplemental balloon data
tomorrow afternoon. The bigger concern regarding convective
development will be the quality and depth of moisture return into
the area given the northerly track of the shortwave. Surface based
instability is expected to be around 2000 J/kg with dewpoints in
the lower 60s, although this moisture is fairly shallow. Mean
layer instability (around 1500 J/kg) will likely be more
representative of the environment tomorrow afternoon from the
Metroplex and areas southward. Most of the high resolution
guidance develops convection to the west-northwest of the
Metroplex by 22Z, although these initial convective attempts
quickly diminish by 00Z. This suggests that the initial
development along the dryline may not have enough support to allow
them to move off the dryline into a more unstable environment.
Forcing will be stronger the farther north, so areas generally
north of I-20 should have a better chance for thunderstorms
through the early evening hours.

Our latest thinking is that the best chance for severe
thunderstorms in our area will be in the Red River counties,
particularly Cooke, Grayson, and Fannin counties, from about 22Z
to 00Z. However, it should be noted that if any storms farther
south can be sustained, then the environment is more than suitable
to support severe weather. Forecast soundings for tomorrow
afternoon feature lapse rates in excess of 8 C/km through a deep
layer along with large clockwise curved hodographs through the
lowest 2 km. While all modes of severe weather will be possible,
the quality/depth of moisture remains the biggest limiting factor
for a more appreciable tornado threat. Very large hail (baseball
size or larger) will be the main severe weather threat through the
evening hours. We`ll maintain 20-30% PoPs across mainly the
northern half of the CWA with the best chances along the Red
River. Any convection that develops will move east through the
evening with a cold front moving into the area during the
overnight hours.

Monday looks like it will be a rather nice day behind the cold
front but it won`t last long. Another strong upper low will
move into the southwest U.S. by Tuesday. This will again allow
moisture to spread northward and rain/storm chances increasing
late Tuesday through Wednesday. There may be an initial severe
weather threat late Tuesday afternoon/evening as convection
develops across West Texas along a dryline and moves eastward.
Rain/storm chances increase significantly across North Texas
Tuesday night into Wednesday where one or more rounds of
thunderstorms may move through the region. At this time, the
severe weather threat does not look overly impressive, although
there will be sufficient instability/shear to support rotating
storms during this time. We`ll monitor this closely over the next
48 hours. Heavy rainfall will be possible through Wednesday with
current forecast rainfall amounts between 2 and 4 inches across
parts of North Texas. While the system looks like it will remain
progressive enough to preclude a more significant flash flood
threat, localized training of storms would support flash flooding.

This system moves east Wednesday night into Thursday with quiet
weather through the end of the week.

Dunn

&&

.AVIATION...
/ISSUED 1258 PM CDT Sat Mar 25 2017/
An area of low clouds around FL030 associated with a synoptic low
pressure circulation continues to pivot eastward. These clouds
will graze DFW Metroplex TAF sites this afternoon but expect
coverage to remain FEW/SCT precluding any low VFR cig mention in
the TAFs. At Waco, SKC conditions will prevail through the rest of
the day. Meanwhile, northwest winds have begin to decrease and
will continue to do so through this evening. Winds are expected to
become light and variable by sunset and remain light overnight.

Early Sunday morning, winds will return to the south. Southerly
flow will bring in an area of modest low-level moisture, possibly
resulting in some ragged MVFR stratus across parts of Central TX.
Have included a tempo mention for cigs around FL015 at Waco but
do not expect cigs at DFW Metroplex sites. South winds will
increase and become gusty by midday with gusts of 20-30 kts
possible. There is a low potential for isolated thunderstorms
which could affect the TAF sites or TRACON cornerposts later
Sunday afternoon, but this potential is too low to include in the
extended DFW TAF at this time.

-Stalley


&&

.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth    55  84  60  80  56 /   0  30  20   0   0
Waco                54  83  62  83  59 /   0  20  20   0   5
Paris               50  80  60  77  53 /   0   5  50   0   0
Denton              51  82  58  78  53 /   0  30  20   0   0
McKinney            49  81  59  78  54 /   0  30  30   0   0
Dallas              55  84  62  81  57 /   0  30  30   0   0
Terrell             50  82  62  79  56 /   0  20  40   0   0
Corsicana           54  84  63  82  60 /   0  10  30   0   0
Temple              54  84  60  84  60 /   0   5  10   0   5
Mineral Wells       52  86  54  80  53 /   0  20  10   0   0

&&

.FWD WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.